Tom Lane wrote on 24.07.2012 17:55:
> Joins on tid columns just aren't supported very well at the moment.
> Partly that's from lack of round tuits, and partly it's because it
> doesn't seem all that wise to encourage people to use them. There
> are gotchas if any of the rows receive concurrent updates.
Thanks for the clarification. I will keep that in mind.
> FWIW, it might be helpful to cast this as a NOT EXISTS rather than
> NOT IN subquery.
Hmm. How would you change that into an NOT EXISTS clause (so that one of the duplicates remains)
Everything I come up with is in fact slower than the NOT IN solution.
Regards
Thomas